The "Detect read features" indicates if the drive reports C2 capability - the Examine C2 feature tests that the drive DOES report C2 on a disc with defects.
Those still don't confirm C2 accuracy.
So, if the known settings or test says:
1. Accurate stream - then check this, as it means that sync/reposition correction is not needed, and most drives are now accurate.
2. Caching - is reported, set this, so that EAC will take cache flushing measures to ensure that re-reads are actually performed instead of cached.
3. C2 if supported, can trade greater ripping speed, for a possible loss in accuracy depending on the drives C2 reporting accuracy - if in doubt, uncheck.